The earth moves around the sun so fast that the sun moves around the Milky Way. Why do the stars in the night sky seem to never change?

In fact, the stars in the night sky are always changing.

take for example

Because of the periodic rotation of the earth's axis. 4800 years ago, Polaris was not the current Polaris (Alpha Ursa minor), but the Draco Alpha. Around 2 100 AD, the angular distance between the sky pointing to the north pole of the earth's rotation axis and Ursa minor α is the smallest. Around 4000 AD, Cepheus γ will become the new north star.

Moreover, astronomers also use the "annual parallax method" to measure the stars close to the earth: that is, the distance between the stars and the earth is calculated by the parallax generated by the annual movement of the earth around the sun.

Then the time-lapse photos of those photographers also showed us that the starry sky was not static.

The earth moves around the sun really fast, and so does the sun around the Milky Way.

But why do the stars seem eternal?

Pay attention to the scale of the universe: the gravitational influence of the solar system is nearly 2 light years, and the nearest star, proxima centauri, is also 4.2 light years away.

Voyager 1 launched in 1970s is now close to the edge of the solar system, and No.2 flew over Neptune many years ago.

They have been traveling in third cosmic velocity for forty years!

With a short life span of one hundred years and a second-level shallow vision,

We have no luck to see the universe through the ages. .

Looking up at the starry sky, the smallness and fragility of human beings and the magnificence of nature are displayed in front of us.

The cycle of life is like the revolution of the earth in the blink of an eye.

The spirit of seeking knowledge remains the same as the starry sky.

I think this is the best lesson the night sky has taught us.